WASHINGTON — A House-Senate budget conference committee is finding its work on a compromise spending plan tough sledding, and the prospects for a long-term federal spending blueprint appear dead.

During recent conversations with Defense News, senior House and Senate aides have acknowledged talks between the leaders of the bicameral conference committee have been plodding, and have so far yielded few tangible plans.

In public statements, their bosses have sounded even less optimistic.

“These budget negotiations are moving way too slowly,” House Budget Committee Ranking Member Rep. Chris Van Hollen, D-Md., said Tuesday. The chairman of that panel, Rep. Paul Ryan, R-Wisc., last week said “we are further along than when we started” — but made clear major differences remain between Republicans and Democrats.

Asked during an interview on MSNBC if a House-Senate budget conference committee will meet congressional appropriators’ demands for a final 2014 budget topline figure by Monday, Van Hollen responded: “The short answer is: No — that would be a minor miracle.”

Congressional sources say the parties — as they have since Barack Obama became president and ultra-conservative members joined Congress — remain far apart on taxes, entitlement reforms, and just where to cut the federal budget.

“The idea of a small [budget] deal is on base, I think,” said one Senate source.

The Senate source said the conference committee’s nitty-gritty work is mostly being done by its co-chairs, Ryan and Senate Budget Committee Chairwoman Sen. Patty Murray, D-Wash.

“Murray and Ryan are doing most of the talking, and then they’re kind of just getting back to the rest of us,” said the source, whose boss is a member of the conference committee.

It is increasingly unlikely that the Ryan-Murray committee will agree to the kind of long-term budget and deficit-paring blueprint it was charged with creating. Instead, aides and lawmakers say what’s most likely is a shorter-spanning — likely two years at the most — plan like the “mini-bargain” long pushed by Senate Appropriations Committee Chairwoman Sen. Barbara Mikulski, D-Md.

So why can’t Democrats and Republicans strike that kind of long-term plan? It depends on which member of which party is answering. Both sides largely blame the other for refusing to negotiate.

“The fundamental issue has been the difference in opinion over some big issues,” Van Hollen said.

“For example, Republicans started the negotiations by taking things off the table,” Van Hollen said. “For example, they said, ‘You can’t replace the sequester, even in part, by eliminating one special-interest tax loophole.’

“When you take that position, it simply makes things harder,” he said. “Essentially, what they’ve said is they’re willing to see dramatic cuts to the budget — including for defense — rather than dealing with some of these special-interest tax breaks.”

A Pentagon spokesman said the Defense Department faces a total sequester cut to all non-exempt accounts in 2014 of $52 billion. DoD civilian and uniformed brass have raised dramatic warnings about the ramification of continued across-the-board cuts.

Van Hollen described Republicans as divided on what to do about the remaining nine years of sequestration.

He said Senate Minority Leader Mitch McConnell, R-Ky., “came over to the House and said, ‘Let’s just settle for sequester at the end of the day.’ ” But members of the House-Senate budget conference panel, he said, got a letter from some House Appropriations Committee Republicans urging the budget conference to “fix” sequestration.

But Ryan, during an event last week sponsored by the Wall Street Journal, largely blamed Democrats for dismissing the notion of replacing some or all remaining sequester cuts with entitlement program changes.

Ryan said that during closed-door talks, Democrats do not pitch entitlement reform changes “of any significance whatsoever.”

“They’re signaling they aren’t interested in entitlement reform in any shape or form,” Ryan said. “If this becomes about raising taxes, we’re not going to get anywhere.”

“We are willing to trade” some of the sequester cuts for other federal spending cuts, he added.

Ryan made clear House Republicans support keeping the defense and domestic sequestration cuts in place — in full — if Democrats refuse to accept the entitlement and tax reforms they want.

“We know … our debt is about to take off in a few years and never come back down if we don’t do something about it,” Ryan said. “This is our concern. What we get from the president is: Give me more debt … without doing anything to deal with why the debt is rising so fast.”

That’s why Republicans want to lock in “a down payment” on curbing the nation’s massive deficit.

Short of a mostly entitlement-reform deal, Ryan said, “then we’ll stick with what we have.”

William Lynn, a former deputy defense secretary, told Defense News editors and reporters on Monday that the department likely could live with the spending levels set in place by the sequester-creating 2011 Budget Control Act.

But he described the mechanism of sequestration as untenable. Removing that so-called “meat axe,” he said, would allow Pentagon and defense industry officials to have more insight about future defense budget levels.

That move “would have a significant effect on mitigating the damage,” Lynn said. “That is the most important step we could take.”

Ryan, the 2012 GOP vice presidential nominee, also predicted there will be no government shutdown when the federal government runs out of funding on Jan. 15.

He believes that either the House-Senate budget conference committee will strike some kind of deal or lawmakers will instead pass another continuing resolution in January.

“One of those two scenarios will prevail, and therefore,” he said, “we will not have a government shutdown.”